On Fri, 2004-12-24 at 10:19 -0500, Doug Eubanks wrote:

mail_never_cache_fields = MessagePart Envelope Body

I updated its comment now:

Space-separated list of fields to initially save into cache file. Currently

these fields are allowed:

flags, date.sent, date.received, size.virtual, size.physical

mime.parts, imap.body, imap.bodystructure

Different IMAP clients work in different ways, so they benefit from

different cached fields. Some do not benefit from them at all. Caching more

than necessary generates useless disk I/O, so you don't want to do that

either.

Dovecot attempts to automatically figure out what client wants and it keeps

only that. However the first few times a mailbox is opened, Dovecot hasn't

yet figured out what client needs, so it may not perform optimally. If you

know what fields the majority of your clients need, it may be useful to set

these fields by hand. If client doesn't actually use them, Dovecot will

eventually drop them.

Usually you should just leave this field alone. The potential benefits are

typically unnoticeable.